PR.yml

name: PR automation
on:
    pull_request_target:
        types: [opened, reopened, edited, ready_for_review]

jobs:
    labeler:
        runs-on: ubuntu-latest
        steps:
            - name: Label PR
              uses: actions/github-script@v5
              with:
                  github-token: ${{ secrets.PAT }}
                  script: |
                      const { owner, repo, number: issue_number } = context.issue;
                      const pr = await github.rest.pulls.get({ owner, repo, pull_number: issue_number });
                      const title = pr.data.title;

                      const titleRegex = /^\[LAB(\d+)\] [a-zA-Z]?\d+$/;
                      const match = title.match(titleRegex);

                      let labNumberStr = undefined;
                      if (match) {
                        labNumberStr = match[1];
                      } else {
                        core.setFailed('PR title does not match the required format. Please use the format: [LAB#] <studentId>.');
                      }

                      const labelToAdd = `lab${labNumberStr}`;
                      if (labNumberStr) {
                        await github.rest.issues.addLabels({ owner, repo, issue_number, labels: [labelToAdd] });
                      }

                      if (pr.data.base.ref === 'main') {
                        core.setFailed('The target branch cannot be main.');
                      }

                      if (labNumberStr < 3 && pr.data.head.ref !== pr.data.base.ref) {
                        core.setFailed('The source branch and target branch must be the same.');
                      }
                      if (labNumberStr >= 3 && pr.data.head.ref !== labelToAdd) {
                        core.setFailed(`The source branch must be '${labelToAdd}'`);
                      }
    checklist-check:
        runs-on: ubuntu-latest
        steps:
            - name: Check PR description
              uses: actions/github-script@v5
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
                  script: |
                      const { owner, repo, number: issue_number } = context.issue;
                      const pr = await github.rest.pulls.get({ owner, repo, pull_number: issue_number });
                      const body = pr.data.body;

                      const checkboxes = body.match(/^ ?(-|\*) \[[x ]\]/gmi);
                      if (!checkboxes || checkboxes.length !== 5) {
                        core.setFailed('The PR description must contain exactly 5 checkboxes.');
                      }

                      const unchecked = body.match(/^ ?(-|\*) \[ \]/gm);
                      if (unchecked && unchecked.length > 0) {
                        core.setFailed(`There are ${unchecked.length} unchecked item(s) in the PR description.`);
                      }